Mini drill bits

Walthers sells the numbered sizes in packs of two.                   Mark Vinski.

Also try larger hardware stores - the real ones, not Home Depot or Lowes.  Most will have drawers with wire guage (#1 to 80) Letter, Fractional and sometime even Metric bits.  For smaller than # 80, you can do a search on the net, but these are both expensive and very fragile.  I have had some luck turning good quality entomology pins into small drills by carefully grinding and filing a "D" shape on the ends for holes in plastic and wood to be drilled by hand.

Kurt

Also, if you have access to a Snap-On Tools dealer, you can 'em from them. The small bits are used to clear fuel injectors! That's where I originally got mine from.

Try Small Parts, McMaster Carr, Grainger, and Brownells.

You are better off buying multiples of the same drill—they are fragile.

Try MSC Industrial Supply.  It'll take some digging (their paper catalogue is something like 5,000 pages) but you'll find that they can supply numbered drill bits down to #97 and digital and metric sizes even smaller.  Only problem is that as they get smaller, they get more expensive and can be bought in multiples of 12 only.

As good a place as any to ask, modelbuilder, and yes, you can get them individually. If you go to Micro-Mark's web site, check out item #'s 15180 (#74), 15181 (#75), 15182(#76), 15183 (#77), and 15184 (#78). Each item # contains 6 bits. Happy modeling!